A walker or walking frame is a tool for disabled or elderly people who need additional support to maintain balance or stability while walking. Typically, a walker includes a lightweight frame that is about waist high, and slightly wider than the user, creating a U-shaped or indented area for the user to stand within. The front two legs of the walker can have wheels attached, depending on the strength and abilities of the person using it.
Another type of tool, similar to the walker, is the rollator, also called a “wheeled walker.” The rollator typically includes a main frame coupled to a posterior frame, with three or four large wheels, handlebars, and a built-in seat, which allows the user to stop and rest when needed. Rollators can also include a basket, permanently or removably coupled to the front of the main frame. Rollators are typically height adjustable and light-weight, yet sturdier than conventional walkers. The handlebars are equipped with hand brakes that can be lifted or pushed downward to instantly stop the rollator by engaging the front and/or rear wheels. The brakes can also be used in maneuvering the rollator; by braking one side while turning the rollator towards that side a much tighter turning radius can be achieved.
As indicated in a biomechanical analysis of rollator walking, published in BioMed, in 2006. “During rollator walking the hip becomes more flexed while the knee and ankle joints were less flexed/dorsiflexed. The ROM [range of motion] of the ankle and knee joints is reduced and there is a reduction in the knee extensor moment by 50%. The ankle plantarflexor and hip abductor moments were smaller when walking with a rollator. The angular impulse of the hip extensors are significantly increased during rollator-walking.”
The traditional walker/rollator is designed to increase stability during locomotion, using the walker/rollator to extend the user's base of support (hereinafter “BOS”). Upper limb movements used during contralateral movement contribute significantly to frontal plane balance and postural stability during locomotion. However, the height, shape, and design of traditional walkers limit upper limb movement. The forearms and hands are placed outside the walker/rollator BOS, with the palms of the hands facing each other. The moment arm between the user's center of mass (hereinafter “COM”) and the walker becomes longer and the knee extensor moment becomes shorter, causing the feet to stop striking the ground from heel to toe during the gait cycle.
The postural stability of the body during locomotion depends on the stability of its individual segments (arms and legs). The part of balance that is contributed by each segment is called a segment's partial equilibrium. Each segment has its own partial center of gravity (hereinafter “COG”) and partial gravity line (hereinafter “LOG”). Any change in position of a partial COG produces a corresponding change in the common center of gravity and the LOG in the body. Movement that maintains the gravity line of the arms and legs during locomotion keeps the body's COM and COG low and centralized inside the BOS. Movement that reduces the ROM of the knee and ankle joints causes a reduction of the knee extensor moment during the gait cycle. When the angular impulse of the hip extensors are significantly increased during locomotion, a stooped, stiff posture with the head and neck bent forward develops causing a shuffle gait that is unrelated to age or disease.
People adapt physically and mentally to the environment in which they move and work. With every movement we make, our conscious brain strives to do better. Repetition and practice of a new motor skill or behavior causes the brain, and not just the body, to adapt. Procedural memory is a form of muscle memory. After 300-500 new attempts at a new motor skill or behavior, the body starts to adapt to the imposed demands placed upon it. New movement or motor behavior starts to become habitual in as little as three weeks. After four and a half months of new neural pathways, good or bad, become the default pathways that the body uses. The body's muscular skeletal system adapts physically to the specific demands placed upon it during locomotion. When there is unstable motion that does not maintain postural alignment and vertical orientation during locomotion, the body stops being able to repair itself from the stress imposed upon it. The skeletal bones become thinner and the skeletal muscles become weaker, the fascia surrounding the muscles and the joints becomes tight and less flexible, and the body stops producing enough joint nourishing, shock absorbing synovial fluid.
There remains a need for an improved walker or rollator design that improves a user postural alignment and therefore stability.